Development of a High Accuracy Luminance Calibration Service for Radioluminous Sources.
Abstract
A technique has been developed for accurately measuring the luminance of (quasi-monochromatic) radioluminous sources (RLS's). This development is part of an overall effort to improve the specification subsequent procurement of low light level RLS's. This technique involves the accurate measurement of spectral radiance of the RLS via a spectroradiometer which has been calibrated directly against a freezing point of gold primary standard blackbody. The spectral radiance is then combined with the appropriate luminosity weighting function (e.g., the C.I.E. (Chromaticity Diagram) photopic eye response), and the luminance is calculated. Measurements on four radioluminous sources calibrated previously by the National Bureau of Standards (NBS) produced agreement to + or - 1% for three sources; and a disagreement of 3% on one source at the 50 microlambert level. Since our process repeatability is about + or - 2%, we have assigned an overall uncertainty of + or - 3.6% for measurements in the 25 - 1500 microlambert range. The main restriction in our technique is that the sources to be calibrated must have a planar surface area of at least 21 and preferably 25 millimeters diameter which radiates uniformly.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 10, 1976
- Accession Number
- ADA035516
Entities
People
- L. Fecteau